Tributes have rained down on Harriet Cass and Charlotte Green since Radio 4 announced that they are to take voluntary redundancy. Easily the best has been a clip of Ms Green reading two news items: about the unearthing of the first-ever recording of a human voice (a rather watery Au Clair de la Lune), then announcing the death of a Hollywood screenwriter. So funny is the French song that, even as she starts on the obit, the newsreader cannot keep down her giggle. She is corpsing: laughing at the worst possible moment. Patrick Stewart, Brian Johnston and Natasha Kaplinsky have all done it. The term comes from how actors would make a colleague playing a corpse convulse with laughter; and it usually charms an audience. Actors and newsreaders are meant to be conduits for other people's lines, but breaking the flow of events with a fit of the giggles reminds us that they are individuals too – with their own funny bones.